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Titov E. Visible Light Induced Exciton Dynamics and trans-to- cis Isomerization in Azobenzene Aggregates: Insights from Surface Hopping/Semiempirical Configuration Interaction Molecular Dynamics Simulations. ACS OMEGA 2024; 9:8520-8532. [PMID: 38405525 PMCID: PMC10882624 DOI: 10.1021/acsomega.3c09900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 01/19/2024] [Accepted: 01/24/2024] [Indexed: 02/27/2024]
Abstract
Assemblies of photochromic molecules feature exciton states, which govern photochemical and photophysical processes in multichromophoric systems. Understanding the photoinduced dynamics of the assemblies requires nonadiabatic treatment involving multiple exciton states and numerous nuclear degrees of freedom, thus posing a challenge for simulations. In this work, we address this challenge for aggregates of azobenzene, a prototypical molecular switch, performing on-the-fly surface hopping calculations combined with semiempirical configuration interaction electronic structure and augmented with transition density matrix analysis to characterize exciton evolution. Specifically, we consider excitation of azobenzene tetramers in the nπ* absorption band located in the visible (blue) part of the electromagnetic spectrum, thus extending our recent work on dynamics after ππ* excitation corresponding to the ultraviolet region [Titov, J. Phys. Chem. C2023, 127, 13678-13688]. We find that the nπ* excitons, which are initially strongly localized by ground-state conformational disorder, undergo further (very strong) localization during short-time photodynamics. This excited-state localization process is extremely ultrafast, occurring within the first 10 fs of photodynamics. We observe virtually no exciton transfer of the localized excitons in the nπ* manifold. However, the transfer may occur via secondary pathways involving ππ* states or the ground state. Moreover, we find that the nπ* quantum yields of the trans-to-cis isomerization are reduced in the aggregated state.
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Affiliation(s)
- Evgenii Titov
- Institute of Chemistry, Theoretical
Chemistry, University of Potsdam, Karl-Liebknecht-Straße 24-25, 14476 Potsdam, Germany
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Titov E, Kopp T, Hoche J, Humeniuk A, Mitrić R. (De)localization dynamics of molecular excitons: comparison of mixed quantum–classical and fully quantum treatments. Phys Chem Chem Phys 2022; 24:12136-12148. [DOI: 10.1039/d2cp00586g] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Molecular excitons play a central role in processes of solar energy conversion, both natural and artificial. It is therefore no wonder that numerous experimental and theoretical investigations in the last...
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Nandi RP, P CAS, Dhanalakshmi P, Behera SK, Thilagar P. Effect of the Molecular Conformation on Excitation Energy Transfer in Conformationally Constrained Boryl-BODIPY Dyads. Inorg Chem 2021; 60:5452-5462. [PMID: 33830747 DOI: 10.1021/acs.inorgchem.0c02739] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We studied the dual emission characteristics of a series of boryl-BODIPYs (1-6) comprised of triarylborane (TAB) as an energy donor and BODIPY as an energy acceptor. The molecular conformations of dyads 1-6 were systematically tuned by judiciously changing the spacer that bridged the boryl and BODIPY moieties. Frontier molecular orbitals (FMOs) are localized in 3, 4, and 6 with a twisted molecular conformation. In contrast, FMOs are significantly delocalized in 1, 2, and 5 with the least-twisted molecular conformation. Dyads 1-6 showed dual emission features when they were excited at the TAB-dominated absorption band. However, the ratio between the two emission bands in 1-6 significantly varied depending on the molecular conformations. Systematic photoluminescence (PL) studies (both steady-state and time-resolved PL) together with computational, crystal structure, and anion binding studies established that the frustrated excited-state energy transfer from borane to BODIPY is the cause of the dual emission features in these molecular dyads. These studies also revealed that the energy transfer from borane to BODIPY can be elegantly tuned by modulating the dihedral angle between these two moieties.
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Affiliation(s)
- Rajendra Prasad Nandi
- Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore 560012, India
| | - Chinna Ayya Swamy P
- Department of Chemistry, National Institute of Technology Calicut, Kozhikode 673601, India
| | - Pandi Dhanalakshmi
- Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore 560012, India
| | - Santosh Kumar Behera
- Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore 560012, India
| | - Pakkirisamy Thilagar
- Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore 560012, India
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Nelson TR, White AJ, Bjorgaard JA, Sifain AE, Zhang Y, Nebgen B, Fernandez-Alberti S, Mozyrsky D, Roitberg AE, Tretiak S. Non-adiabatic Excited-State Molecular Dynamics: Theory and Applications for Modeling Photophysics in Extended Molecular Materials. Chem Rev 2020; 120:2215-2287. [PMID: 32040312 DOI: 10.1021/acs.chemrev.9b00447] [Citation(s) in RCA: 213] [Impact Index Per Article: 53.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Optically active molecular materials, such as organic conjugated polymers and biological systems, are characterized by strong coupling between electronic and vibrational degrees of freedom. Typically, simulations must go beyond the Born-Oppenheimer approximation to account for non-adiabatic coupling between excited states. Indeed, non-adiabatic dynamics is commonly associated with exciton dynamics and photophysics involving charge and energy transfer, as well as exciton dissociation and charge recombination. Understanding the photoinduced dynamics in such materials is vital to providing an accurate description of exciton formation, evolution, and decay. This interdisciplinary field has matured significantly over the past decades. Formulation of new theoretical frameworks, development of more efficient and accurate computational algorithms, and evolution of high-performance computer hardware has extended these simulations to very large molecular systems with hundreds of atoms, including numerous studies of organic semiconductors and biomolecules. In this Review, we will describe recent theoretical advances including treatment of electronic decoherence in surface-hopping methods, the role of solvent effects, trivial unavoided crossings, analysis of data based on transition densities, and efficient computational implementations of these numerical methods. We also emphasize newly developed semiclassical approaches, based on the Gaussian approximation, which retain phase and width information to account for significant decoherence and interference effects while maintaining the high efficiency of surface-hopping approaches. The above developments have been employed to successfully describe photophysics in a variety of molecular materials.
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Affiliation(s)
- Tammie R Nelson
- Theoretical Division , Los Alamos National Laboratory , Los Alamos , New Mexico 87545 , United States
| | - Alexander J White
- Theoretical Division , Los Alamos National Laboratory , Los Alamos , New Mexico 87545 , United States
| | - Josiah A Bjorgaard
- Theoretical Division , Los Alamos National Laboratory , Los Alamos , New Mexico 87545 , United States
| | - Andrew E Sifain
- Theoretical Division , Los Alamos National Laboratory , Los Alamos , New Mexico 87545 , United States.,U.S. Army Research Laboratory , Aberdeen Proving Ground , Maryland 21005 , United States
| | - Yu Zhang
- Theoretical Division , Los Alamos National Laboratory , Los Alamos , New Mexico 87545 , United States
| | - Benjamin Nebgen
- Theoretical Division , Los Alamos National Laboratory , Los Alamos , New Mexico 87545 , United States
| | | | - Dmitry Mozyrsky
- Theoretical Division , Los Alamos National Laboratory , Los Alamos , New Mexico 87545 , United States
| | - Adrian E Roitberg
- Department of Chemistry , University of Florida , Gainesville , Florida 32611 , United States
| | - Sergei Tretiak
- Theoretical Division , Los Alamos National Laboratory , Los Alamos , New Mexico 87545 , United States
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Deng T, Hong P, Hao C, Fu Y. TDDFT investigation on the solvent effect of methanol on the electronic structure and luminescence of metal organic framework CdL2. Chem Phys 2019. [DOI: 10.1016/j.chemphys.2019.03.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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Huang YC, Cheng YC. C-N Bond Rotation Controls Photoinduced Electron Transfer in an Aminostyrene-Stilbene Donor-Acceptor System. J Phys Chem A 2019; 123:4333-4341. [PMID: 31034231 DOI: 10.1021/acs.jpca.9b00856] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We investigate energy transfer and electron transfer in a dimethylsilylene-spaced aminostyrene-stilbene donor-acceptor dimer using time-dependent density functional theory calculations. Our results confirm that the vertical S3, S2, and S1 excited states are, respectively, a local excitation on the aminostyrene, local excitation on the stilbene, and the charge-transferred (CT) excited state with electron transfer from aminostyrene to stilbene. In addition, an energy minimum with the C-N bond of the amino group twisted at about 90° is also identified on the S1 potential energy surface. This S1 state exhibits a twisted intramolecular charge transfer (TICT) character. A potential energy scan along the C-N bond torsional angle reveals a conical intersection between the S2 stilbene local excitation and the S1 CT/TICT state at a torsional angle of ∼60°. We thus propose that the conical intersection dominates the electron transfer dynamics in the donor-acceptor dimer and copolymers alike, and the energy barrier along the C-N bond rotation controls the efficiency of such a process. Moreover, we show that despite the zero oscillator strength of the S1 excited states in the CT and TICT minima, an emissive S1 state with a V-shaped conformational structure can be located. The energy of this V-shape CT structure is thermally accessible; therefore, it is expected to be responsible for the CT emission band of the dimer observed in polar solvents. Our data provide a clear explanation of the complex solvent-dependent dual emission and photoinduced electron transfer properties observed experimentally in the dimer and copolymer systems. More importantly, the identifications of the conical intersection and energy barrier along the C-N bond rotation provide a novel synthetic route for controlling emissive properties and electron transfer dynamics in similar systems, which might be useful in the design of novel organic optoelectronic materials.
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Affiliation(s)
- Yen-Chin Huang
- Department of Chemistry , National Taiwan University , No. 1, Sec. 4, Roosevelt Rd. , Da-an District, Taipei City 106 , Taiwan
| | - Yuan-Chung Cheng
- Department of Chemistry , National Taiwan University , No. 1, Sec. 4, Roosevelt Rd. , Da-an District, Taipei City 106 , Taiwan
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Titov E, Humeniuk A, Mitrić R. Exciton localization in excited-state dynamics of a tetracene trimer: a surface hopping LC-TDDFTB study. Phys Chem Chem Phys 2018; 20:25995-26007. [PMID: 30298878 DOI: 10.1039/c8cp05240a] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Excitons in the molecular aggregates of chromophores are key participants in important processes such as photosynthesis or the functioning of organic photovoltaic devices. Therefore, the exploration of exciton dynamics is crucial. Here we report on exciton localization during excited-state dynamics of the recently synthesized tetracene trimer [Liu et al., Org. Lett., 2017, 19, 580]. We employ the surface hopping approach to nonadiabatic molecular dynamics in conjunction with the long-range corrected time-dependent density functional tight binding (LC-TDDFTB) method [Humeniuk and Mitrić, Comput. Phys. Commun., 2017, 221, 174]. Utilizing a set of descriptors based on the transition density matrix, we perform comprehensive analysis of exciton dynamics. The obtained results reveal an ultrafast exciton localization to a single tetracene unit of the trimer during excited-state dynamics, along with exciton transfer between units.
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Affiliation(s)
- Evgenii Titov
- Institut für Physikalische und Theoretische Chemie, Julius-Maximilians-Universität Würzburg, Emil-Fischer-Straße 42, 97074 Würzburg, Germany.
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Hu D, Liu YF, Sobolewski AL, Lan Z. Nonadiabatic dynamics simulation of keto isocytosine: a comparison of dynamical performance of different electronic-structure methods. Phys Chem Chem Phys 2017; 19:19168-19177. [DOI: 10.1039/c7cp01732d] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Different reaction channels are obtained in the nonadiabatic dynamics simulations of isocytosine at CASSCF and ADC(2) levels.
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Affiliation(s)
- Deping Hu
- Key Laboratory of Biobased Materials
- Qingdao Institute of Bioenergy and Bioprocess Technology
- Chinese Academy of Sciences
- Qingdao
- People's Republic of China
| | - Yan Fang Liu
- Key Laboratory of Biobased Materials
- Qingdao Institute of Bioenergy and Bioprocess Technology
- Chinese Academy of Sciences
- Qingdao
- People's Republic of China
| | | | - Zhenggang Lan
- Key Laboratory of Biobased Materials
- Qingdao Institute of Bioenergy and Bioprocess Technology
- Chinese Academy of Sciences
- Qingdao
- People's Republic of China
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Singh G, Ardolic H, Peetz RM. Studies on homologous random and alternating segmented conjugated polymers with and without silicon synthesized by ADMET. Polym Chem 2016. [DOI: 10.1039/c5py01455g] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Using acyclic diene metathesis (ADMET), we synthesized homologous luminescent conjugated polymers with two aromatic segments based on thiophene and substituted phenylene, either alternating or randomly distributed, and either directly connected or separated by Si-linkers.
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Affiliation(s)
- Gagandeep Singh
- City University of New York
- Graduate Center and College of Staten Island
- 2800 Victory Boulevard
- USA
- Ph.D. Program in Chemistry
| | - Hamid Ardolic
- City University of New York
- Graduate Center and College of Staten Island
- 2800 Victory Boulevard
- USA
| | - Ralf M. Peetz
- City University of New York
- Graduate Center and College of Staten Island
- 2800 Victory Boulevard
- USA
- Ph.D. Program in Chemistry
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